# Navajo Nation Nuclear Energy

## Benjamin Wheeler November 28, 2010

### Submitted as coursework for Physics 240, Stanford University, Fall 2010

During the 20th century nuclear power became a viable option as technologies developed that could harness the atomic reactions of radioactive elements. Today, nuclear energy is a highly controversial source that has the potential to move the world off of coal and oil, but could also result in a multitude of problems from radiation. Historically uranium was mined in the United States to fuel the Manhattan Project and later to produce weapons during the Cold War. A major site for mining this material was the Navajo Nation from 1944 to 1986. Judy Pasternak's research and article in the Los Angeles Times revealed many health concerns from mines that produced 3.9 million tons of uranium ore during their operation. [1] This report seeks to determine how much energy that uranium ore could have produced if used for electric power rather than nuclear weapons.

According to Richard Muller's calculations, every fission of a U-235 atom produces about 215 MeV or 3.44 × 10-11 Joules of energy. [2] U-235 is only 0.7% of natural uranium, with U-238 making up 99.3%, so we have .007 × 3.9 million tons = 2.73 × 108 kg of U-235. A mole is 6.02 × 1023 atoms and weighs 0.235 kg, thus the contained energy is

6.02 × 1023 atoms/mole × 3.44 × 10-11 joules/atom × 2.72 × 107 kg / 0.235kg/mole = 2.40 x 1021 joules

Muller states that only a third of that energy actually becomes electricity, so there is actually 7.99 x 1020 joules.

The Navajo Nation possesses a population of 250,000. [3] According to Richard Eden in Energy Economics, the consumption of electricity per person in the United States is roughly 104 kWh or 3.6 × 1010 joules per year [4].

3.6 × 1010 × 250,000 = 9.0 × 1015 joules

The amount of energy from the uranium divided by the annual consumption of electricity for the Navajo Nation by population is

6.3 × 1020 joules / 9.0 × 1015 joules/year = 70,000 years

The amount of uranium removed from the Navajo Nation through rough estimates could have supplied the power required for the Navajo population for 70,000 years.

© Benjamin Wheeler. The author grants permission to copy, distribute and display this work in unaltered form, with the attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

## References

[1] Judy Pasternak, " A Peril that Dwelt Among the Navajos," Los Angeles Times, 19 Nov06.

[2] R. A. Muller, Physics and Technology for Future Presidents (Princeton University Press, 2010), p. 182.

[3] Sandra Pasqua, The Navajo Nation (Capstone Press, 2000), p. 9.

[4] Richard Eden et al., Energy Economics: Growth, Resources, and Policies (Cambridge University Press, 1981) p. 155-156.